1. Field of the Invention
The present invention relates to vascular prostheses that contain hormone-producing cells in microcapsule form.
2. Description of Related Art
Microcapsules consisting of saccharide, amino-acid polymers and other materials, such as agarose polymers, are already known and are apt to contain living hormone-producing cells.
Microcapsules with the above-mentioned features are manufactured and marketed by Damon, Biotech of Boston under the name of Encapcell, and also by other laboratories.
These microcapsules allow for the protection of the cells contained inside the microcapsules against a possible rejection phenomena, while allowing the metabolic activity of the cells to continue and permit the leaking out of the hormones secreted by the cells.
However, the introduction of such microcapsules in the body brings about some problems, among which the following should be emphasized:
1) the microcapsules introduced in the body are wrapped in a reactive connective tissue, which prevents both the metabolic supply to the cells and the leaking out of the secreted hormones;
2) the microcapsules, if injected into a cavity such as the peritoneal cavity, tend to move downwards and concentrate in a limited area, thus causing a lively connective reaction involving them.